Intestinal protozoan infection is a common cause of gastrointestinal disorders, especially in children. This study was conducted 1.288 stool samples of primary school children age in some suburban and urban districts of Hanoi. The purpose of this study understand the situation of intestinal protozoan infections in children. Two classification methods is tested using a direct method and Formalin-Ether technique. The protozoan infection rate in children is generally 5.12 percent. There are 5 species of protozoan children infection which have been found as E. coli of 2.25 percent, E. histolitica 1.55 percent, G. lamblia 1.16 percent, E. harmani 0.47 percent and E. nana 0.08 percent. In particular, childem in inner-city elementary intestinal protozoan infection is 3.00 percent, in the suburbs is 6.98 percent. There are some high risk factors such as environment, family occupation, use unhygienic latrines, malnutrition status. Results of this study showed that protozoan infection actually affect the health of students.